livetrax/libs/canvas/canvas/wave_view.h

/*
    Copyright (C) 2011-2013 Paul Davis
    Author: Carl Hetherington <cth@carlh.net>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#include <boost/shared_ptr.hpp>
#include <boost/shared_array.hpp>
#include <boost/scoped_array.hpp>

#include "pbd/properties.h"

#include "ardour/types.h"

#include <glibmm/refptr.h>

#include "canvas/visibility.h"
#include "canvas/item.h"
#include "canvas/fill.h"
#include "canvas/outline.h"

namespace ARDOUR {
	class AudioRegion;
}

namespace Gdk {
	class Pixbuf;
}

class WaveViewTest;
	
namespace ArdourCanvas {

class LIBCANVAS_API WaveView : public Item
{
public:

        enum Shape { 
		Normal,
		Rectified
        };

	struct CacheEntry {
		int channel;
		Coord height;
		float amplitude;
		Color fill_color;
		framepos_t start;
		framepos_t end;
		Cairo::RefPtr<Cairo::ImageSurface> image;

	CacheEntry(int chan, Coord hght, float amp, Color fcl, framepos_t strt, framepos_t ed, Cairo::RefPtr<Cairo::ImageSurface> img)  :
		
		channel (chan), height (hght), amplitude (amp), fill_color (fcl), 
			start (strt), end (ed), image (img) {} 
	};

	/* final ImageSurface rendered with colours */
	Cairo::RefPtr<Cairo::ImageSurface> _image;
	
    /* Displays a single channel of waveform data for the given Region.

       x = 0 in the waveview corresponds to the first waveform datum taken
       from region->start() samples into the source data.

       x = N in the waveview corresponds to the (N * spp)'th sample 
       measured from region->start() into the source data.

       when drawing, we will map the zeroth-pixel of the waveview
       into a window. 

       The waveview itself contains a set of pre-rendered Cairo::ImageSurfaces
       that cache sections of the display. This is filled on-demand and
       never cleared until something explicitly marks the cache invalid
       (such as a change in samples_per_pixel, the log scaling, rectified or
       other view parameters).
    */


	WaveView (Canvas *, boost::shared_ptr<ARDOUR::AudioRegion>);
	WaveView (Item*, boost::shared_ptr<ARDOUR::AudioRegion>);
       ~WaveView ();

	void render (Rect const & area, Cairo::RefPtr<Cairo::Context>) const;
	void compute_bounding_box () const;
    
	void set_samples_per_pixel (double);
	void set_height (Distance);
	void set_channel (int);
	void set_region_start (ARDOUR::frameoffset_t);

	/** Change the first position drawn by @param pixels.
	 * @param pixels must be positive. This is used by
	 * AudioRegionViews in Ardour to avoid drawing the
	 * first pixel of a waveform, and exists in case
	 * there are uses for WaveView where we do not
	 * want this behaviour.
	 */
	void set_start_shift (double pixels);
	
        void set_fill_color (Color);
        void set_outline_color (Color);
	
	void region_resized ();
        void gain_changed ();

        void set_show_zero_line (bool);
        bool show_zero_line() const { return _show_zero; }
        void set_zero_color (Color);
        void set_clip_color (Color);
        void set_logscaled (bool);
        void set_gradient_depth (double);
        double gradient_depth() const { return _gradient_depth; }
        void set_shape (Shape);

        /* currently missing because we don't need them (yet):
	   set_shape_independent();
	   set_logscaled_independent()
        */

        static void set_global_gradient_depth (double);
        static void set_global_logscaled (bool);
        static void set_global_shape (Shape);
        static void set_global_show_waveform_clipping (bool);
    
        static double  global_gradient_depth()  { return _global_gradient_depth; }
        static bool    global_logscaled()  { return _global_logscaled; }
        static Shape   global_shape()  { return _global_shape; }

        void set_amplitude_above_axis (double v);
        double amplitude_above_axis () const { return _amplitude_above_axis; }

	static void set_clip_level (double dB);
	static PBD::Signal0<void> ClipLevelChanged;

#ifdef CANVAS_COMPATIBILITY	
	void*& property_gain_src () {
		return _foo_void;
	}
	void*& property_gain_function () {
		return _foo_void;
	}
private:
	void* _foo_void;

#endif

        friend class ::WaveViewTest;

	static std::map <boost::shared_ptr<ARDOUR::AudioSource>, std::vector <CacheEntry> > _image_cache;
	void consolidate_image_cache () const;
	void invalidate_source (boost::weak_ptr<ARDOUR::AudioSource>);
	void invalidate_image_cache ();

	boost::shared_ptr<ARDOUR::AudioRegion> _region;
	int    _channel;
	double _samples_per_pixel;
	Coord  _height;
        bool   _show_zero;
        Color  _zero_color;
        Color  _clip_color;
        bool   _logscaled;
        Shape  _shape;
        double _gradient_depth;
        bool   _shape_independent;
        bool   _logscaled_independent;
        bool   _gradient_depth_independent;
        double _amplitude_above_axis;
	float  _region_amplitude;
	double _start_shift;
	
	/** The `start' value to use for the region; we can't use the region's
	 *  value as the crossfade editor needs to alter it.
	 */
	ARDOUR::frameoffset_t _region_start;

        PBD::ScopedConnectionList invalidation_connection;
	PBD::ScopedConnection _source_invalidated_connection;

        static double _global_gradient_depth;
        static bool   _global_logscaled;
        static Shape  _global_shape;
        static bool   _global_show_waveform_clipping;
	static double _clip_level;

        static PBD::Signal0<void> VisualPropertiesChanged;

        void handle_visual_property_change ();
        void handle_clip_level_change ();

	void get_image (Cairo::RefPtr<Cairo::ImageSurface>& image, framepos_t start, framepos_t end, double& image_offset) const;

        ArdourCanvas::Coord y_extent (double, bool) const;
	void draw_absent_image (Cairo::RefPtr<Cairo::ImageSurface>&, ARDOUR::PeakData*, int) const;
	void draw_image (Cairo::RefPtr<Cairo::ImageSurface>&, ARDOUR::PeakData*, int) const;
};

}